State of the art hearing devices are commonly either behind-the-ear (BTE) hearing devices, in-the-ear (ITE) hearing devices, in-the-canal (ITC) hearing devices or completely-in-the-canal (CIC) hearing devices. BTE hearing devices comprises sound conduction tubes to transmit the amplified sound from the BTE hearing device arranged behind the ear into the user's ear canal. The other hearing devices, ITE, ITC and CIC, are already arranged at or in the ear canal and thus have only short sound conduction tubes or no tubes at all.
Although the ITC and especially CIC hearing devices are preferred by many users due to their low visibility from outside, their drawbacks of limited maximum amplification, limited battery lifetime, limited receiver quality and not suitable space within the ear canal, also BTE hearing devices are still demanded and will still be used in the future.
In order to combine the advantages of BTE hearing devices and ITE, ITC and CIC hearing devices, combined hearing devices have already been proposed, comprising essentially two separate parts. The first part comprises most of the electronic modules, such as micro processors, tuners, power source, regularly in form of replaceable or re-chargeable batteries, and microphones, and is adapted to be worn externally by the user, either behind the ear or to be clipped to the clothing of the user. This part will be called the BTE part. The second part comprises an output transducer, regularly a speaker, and a shell, which is adapted or shaped to be worn partially or completely within the ear canal. This part will be called ITC or CIC part respectively. Those two parts are usually connected to each other by permanently wired connections.
In the field of hearing aids, the electric-to-acoustic transducer, regularly a speaker, is called receiver, as it will be done further on in this description.
Conventionally, the receiver is completely incorporated within the shell of said second ITC or CIC part and firmly connected to the electrical connectors. In case of failure or defect of the receiver, the whole ITC or CIC part has to be replaced, e.g. the shell and regularly also the connectors together with the defective receiver.
If the shell of this second part is custom shaped, a replacement of the receiver is therefore always coupled with a new manufacturing of a new custom shaped shell. That is a time consuming and costly process that may often only be performed by specialized fitting laboratories or the manufacturer of the hearing device. Time consuming means that the user will have to wait several days or even weeks until receiving a replacement part.
A modular connector system for auditory devices of the type of combined BTE/CIC is known from WO2004/025990. The BTE-component of this earpiece auditory device is connected via a connector to the CIC-component comprising the receiver.
The connector consists of a hollow tube with electric wires within this tube. The connector is either hard wire coupled or detachably coupled to the receiver and thus to the CIC-component. The receiver is coupled to the shell of the CIC-component either by mean of a fastener or directly plugged into an opening of the shell. The shell may include an ear mold to be inserted into the ear canal of the user.
The fastener is either fixed to the shell by resilient snap-in tongues or by means of screws. The use of the resilient snap-in tongues allows an easy assembling of the fastener, but is only suitable if the shell of the CIC-component includes a soft ear mold, that may be squeezed to loosen the tongues for a non-destructive disassembling of the fastener and therefore of the connector. Such a fastening means is not suitable in case of rigid shells, as the fasteners may not be disassembled without breaking at least a part of the shell or the fastening means. In any case, this can only be done by specialists skilled in the art.
The use of detachable connecting means such as screws on the other hand requires a well-skilled and time-consuming assembling technique and further disturbs the regularly smooth shape of the outer surface of the housing of the CIC-component. Furthermore, the screws require a certain amount of space in its axial direction which is opponent to the requirement of miniaturization and reduces the freedom of design of the shape of the housing of the CIC-component. Thus, only a limited miniaturization is possible, as well as not all possible ear canal geometries may be covered by such a construction.
All those connecting means further suffer from being prone to contamination with wear debris, dust or humidity. Especially an electrical plug-in connection will thus decrease in its transmitting quality, if it is not securely sealed against such contamination.